From Graduate School of Business and Public Policy, Naval Postgraduate School, Monterey, CA (Y.-C.S.); National Bureau of Economic Research, Cambridge, MA (Y.-C.S.); and Department of Emergency Medicine and Philip R. Lee Institute for Health Policy Studies, University of California at San Francisco (R.Y.H.).

From Graduate School of Business and Public Policy, Naval Postgraduate School, Monterey, CA (Y.-C.S.); National Bureau of Economic Research, Cambridge, MA (Y.-C.S.); and Department of Emergency Medicine and Philip R. Lee Institute for Health Policy Studies, University of California at San Francisco (R.Y.H.).

Within the past 2 decades, the annual number of emergency department (ED) visits increased >40%, but the number of EDs decreased by 11%.1 The closure of an ED can have a profound effect on a community,2–5 because patients have to drive farther to obtain care, and the remaining EDs have to bear the extra patient volume, especially for patients experiencing time-sensitive illnesses requiring prompt intervention, such as acute myocardial infarction.

With patient data from 100% Medicare Provider Analysis and Review between 2001 and 2011 (1.35 million patients), linked with the Healthcare Provider Cost Reporting Information System and American Hospital Association Annual Surveys, we compare changes in access to cardiac technology (availability of catheterization laboratory, cardiac care unit, and cardiac surgery capacity), treatment received (percutaneous transluminal coronary angioplasty and thrombolytic therapy), and health outcomes (30-day, 90-day, and 1-year mortality) among Medicare patients with acute myocardial infarction whose communities experience varying degrees of increase in driving time to their next available ED when the closest ED to the community shuts down, relative to patients from communities that do not experience any permanent ED closure.